Milwaukee



o halt an hour,

' brushes for electric motors and dynamos; and

UNITED Smarts Parent @rrrcn,

ROBE l'l lllRSUll AED HERMAN hll lhllN Gltlt, (ll .lllhll'rlllllltl l, \l'lStUXblN.

CQMMUTATOR-BRUSH.

SPECIFICATION forming part of Letters Patent No. 474,600, dated May 10, 1892.

Application filed December 11, 1891.

To all whom, it may concern:

Be it known that we, ROBERT HIRSCH and HERMAN llIEMINGER, citizens of the United States, and residents of Milwaukee, in the county of Milwaukee, and in the State of \Visconsin, have invented certain new and useful Improvements in Commutator-Brushes; and we do hereby declare that the following is a full, clear, and exact description thereof.

Our invention relates to commutatorit consists in a method of making the brush, as well as in the article itself, all as will be fully set forth hereinafter and subsequently claimed.

Our said invention is, in part, an improvement on that set forth in the application of [3006]! H 719011, filer? 0ct0ber29, 1891,8crial N o. &l ),1G5, and our brushes designed to accoinplrsn the same results as set forth in said application.

In constructing our present brushes we take refined clay and powdered graphite in. the proportions of one and one-half pounds mix them together in the presence of sufficzent Water to make a stiff paste, and after the ii'igredients are thoroughly mixed the mass is compressed into a bar ofproper height and width, according to the size and style of brush desired, and from this bar sections are cut oil? of any length or lengths desired. These sections are then dried and baked or hiuutl ill ll in l l l v. v i l nace or kiln protected llOlh Olllhlllbrlll. baked sections are then immersed in a ha i, preferably of linseed-oil, in a hot state lltllllll the sections have absorbed all the oil wine 1 they Will take, which usually requires about more or less. lhcy arc hhhh in i t hurt urn u r time u r r Serial No. 414,72096- (No model.)

in the shortest time. These reburned sections are now again heated and saturated with wax, (such as beeswax or paraffine,) the heat being sufficient to melt the wax and cause it to be absorbed. The brushes are now ready to receive a coating of metal, pref; erably copper, which may be applied in'any suitable manner, preferably by the process of electro-deposition.

These brushes may either be used singly or a number of small brushes or sections may be placed side by side and united by a second film of electrically-deposited metal, as in the former application hereinbefore referred to.

Having thus described our invention, what we claim, and desire to secure by Letters Pat-" cut, is-

brushes, consisting in mixing together rehnotl clay, graphite, and water into astiif paste and compressing the same into bars, cutting the latter into sections of suitable lengths for brushes, drying and then baking or burning filin of metal, substantially as set forth.

2. The herein-described commutator-brush,

com osed of a mixture of refined clay, gra hih, urhrl'lllll hi hi illllilh (hi n ic routing, substantially as so 'u'ith a iuclall forth.

In testimony that we claim the foregoing we have hereunto set our hands, at hlllwaulltta, i the county cl Milwaukee and state of is cousin. in the urcscucc oi two uuuctscs.

l. The method of forming commutator-"65 

